Prime Minister John Key has reacted to two new polls showing an increase in support for Labour, saying some recovery for the party is natural.

A One News-Colmar Brunton poll released last night and taken a week after Labour’s leadership spat, saw the party’s vote lift 3 percentage points to 35 per cent, with the Greens up one on 13 per cent.

That would give Labour and the Greens the numbers to govern alone.

National was down one on 44 per cent, and NZ First slipped below the 5 per cent threshold to 4 per cent.

Meanwhile, a 3News-Reid Research poll, also released yesterday, showed Labour on the rise at 34.6 per cent, up 1.6 percentage points. The Greens improved 1.3 to 12.9 per cent, while National was down 1.8 at 47 per cent.

With NZ First on just 2 per cent in the 3News poll, the Maori Party would probably hold the balance of power if it retained its three seats.

Key acknowledged National faced a "challenge" with potential coalition partners at the next election.

"So, for a start off, NZ First would go with Labour, but the question is would NZ First get back, because a lot of Labour voters voted NZ First in 2011 because they knew their team wasn't going to get there."

He thought voters would choose National because "the Greens with Labour will stop economic growth. I think that's what New Zealanders will be confronted with."

Challenged about job losses under National's watch, Key said it had to be accepted times were tough and tough decisions needed to be made.

"We're on the right track to resolve those issues over time, but I accept that there's frustrations and things aren't going as fast as people would want," he told Breakfast.LEADERSHIP SPAT’S SILVER LINING

Labour leader David Shearer's tough line on rival David Cunliffe, combined with a bold new housing policy, boosted his party's support, according to the polls.

It also appeared to have also helped his personal ratings too, and he was up 4 points to 15 per cent as preferred prime minister in the One News-Colmar Brunton poll.

John Key slid three to 39 per cent - the first time for four years the prime minister's rating has slipped below 40 per cent. NZ First leader Winston Peters was steady on 6 per cent.

In the 3News poll Key was at his lowest ebb in the preferred prime minister stakes, at 37.4 per cent against 12.6 per cent for Shearer.

The One News poll of 1000 had a margin of error of 3.1 per cent.

It was taken between November 24 and 28, the week after Labour's annual conference exposed divisions in the party but also after Shearer's widely praised keynote address.